The present disclosure relates generally to the field of drilling fluid telemetry systems and, more particularly, to a pulser for modulating the pressure of a flowing drilling fluid.
Sensors may be positioned at the lower end of a well drilling string which, while drilling is in progress, continuously or intermittently monitor various drilling parameters and formation data and transmit the information to a surface detector by some form of telemetry. Such techniques are termed “measurement while drilling” or MWD. MWD may result in a major savings in drilling time and improve the quality of the well compared, for example, to conventional logging techniques. The MWD system may employ a system of telemetry in which the data acquired by the sensors is transmitted to a receiver located on the surface. Fluid signal telemetry, also called mud pulse telemetry, is one of the most widely used telemetry systems for MWD applications.
Fluid signal telemetry creates pressure pulse patterns in the flowing drilling fluid circulated under pressure through the drill string during drilling operations. The information that is acquired by the downhole sensors is transmitted by suitably encoding the information into the pressure pulses in the fluid stream. The encoded pressure pulses may be detected by a sensor attached to a high-pressure flow line, at the surface. The information may be decoded and used for controlling the drilling operation.
While the examples shown are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the present disclosure as defined by the appended claims.